• Title/Summary/Keyword: Vane expander

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A Combined Rotary Compressor-vane Expander (일체형 로타리 압축기-베인 팽창기)

  • Kim, Hyun Jin;No, Young Jae;Kim, Yong Hee
    • The KSFM Journal of Fluid Machinery
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    • v.18 no.3
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    • pp.12-19
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    • 2015
  • As a means of improving cycle performance of a R410A air-conditioning system, a combined structure of compressor and expander was introduced. A vane rotary type expander was designed to share a common shaft with twin type rolling piston rotary compressor in a housing. Numerical simulation on the performance of the combined compressor and expander was carried out. At ARI condition, the volumetric and total efficiencies of the designed vane expander were 69.37% and 30.23%, respectively. With the application of this expander, the compressor input was reduced by 3.91%, and the cooling capacity was increased by 3.98%. As a result, COP of the air-conditioning system was improved by 8.2%. As the pressure difference between the condenser and the evaporator becomes large, COP improvement increases unless the mass flow rate in the expander exceeds that in the compressor.

An Analysis of the Performance of a Combined Expander-Compressor Unit for a CO2 Automotive Air Conditioning Cycle (차량용 CO2 에어컨 사이클 성능 향상을 위한 일체형 팽창기-압축기 성능 해석)

  • Choi, Jae Woong;Lim, Jeong Taek;Kim, Hyun Jin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.30 no.3
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    • pp.107-115
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    • 2018
  • A design combining the use of a compressor and expander was introduced in order to improve the cycle performance of a $CO_2$ automotive air conditioning system. Both the compressor and expander used were of rotary vane type and were designed to share a common shaft in a housing. Numerical simulation was carried out to evaluate the merit of the combined unit. In a typical automotive air conditioning operating conditions, the COP of the system was improved by 8.7% by the application of the combined unit. The compressor input was reduced by 5.2% through use of the expander output. In addition, about 3.06% increase in the cooling capacity was obtained through isentropic expansion in the expander. Our study noted that, as the pressure difference between the gas cooler and the evaporator becomes larger, the COP of the system improved increases unless the mass flow rate in the expander exceeds that in the compressor.

Performance Analysis of Vane Rotary Expander for $CO_2$ Cycles ($CO_2$ 사이클용 로타리 베인 팽창기 성능해석)

  • Kim, Ho-Young;Ahn, Jong-Min;Kim, Hyun-Jin;Cho, Sung-Oug
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.1
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    • pp.55-62
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    • 2009
  • Relatively low cycle performance of a conventional $CO_2$ system is partly due to significant increase in friction loss in the expansion process, since the pressure drop across the expansion device is considerably large compared to a conventional refrigeration cycle. To recover friction loss and increase refrigeration effect by providing isentropic expansion, a rotary vane type expander has been designed. Performance of the designed expander has been investigated by numerical simulation. With the pressure condition of 9 MPa/4.5 MPa and inlet temperature of $35^{\circ}C$, volumetric, isentropic, and mechanical efficiencies of the expander are calculated to be 58.1%, 101.1%, and 78.8%, respectively, resulting in total expander efficiency of 46.3%. With this expander, COP of a $CO_2$ refrigeration cycle is estimated to be improved by about 14%.

Experimental Study of Vane Expander Prototype Applied to Micro Organic Rankine Cycle (초소형 유기랭킨사이클 적용 프로토 타입 베인 팽창기에 관한 실험적 연구)

  • Shin, Dong Gil;Kim, Young Min
    • Journal of Energy Engineering
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    • v.23 no.4
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    • pp.230-235
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    • 2014
  • In this study, performances of the vane expander protype for micro organic Rankine cycle with refrigerant R134a as a working fluid have been analyzed. While operating organic Rankine cycle for analysing expander efficiencies such as overall efficiencies, volumetric efficiencies and mechanical efficiencies under $110^{\circ}C$ of expander inlet temperature, the power of the expander, inlet temperature of expander, inlet pressure of expander and the flow rate of the working fluid(refrigerant R134a) have been measured while varying the rotational speed of the expander. It was found that the more the expander revolution speed is high, the more the expander power, overall efficiencies and volumetric efficiencies are higher. In case of 500 rpm of rotational speed, overall efficiencies are 6~7% and in case of 1000 rpm, overall efficiencies are 11~12%. We have found that low volumetric efficiencies result in poor overall efficiencies.